farrar



No. 6l4,095.

Patented Nov. |5,. l898.

w. M. FARRAR. GAB PROPULSION. (Application filed Oct. 21, 1897.)

2 Sheets-Sheet I.

-(N0 Model.)

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N0. .6l4,095. Patented Nov. I5, I898. w. m. FARRAB.

CAR PROPULSION.

' (Application filed. Oct. 21, 1597.

(No Model.) 2 Sheets-Sheet 195. 15/4 Z4 M? W I a lllmnul ill! 3 l I l 14816511 f'a'nzu:

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UNITED STATES PATENT OFFICE.

WVILLIAM M. FABRAR, OF I-IOBOKEN, NEl/V JERSEY.-

CAR PROPULSION.

srEoIrIcArIoN forming part of Letters Patent No. 614,095, dated November 15, 1898. Application filed October 21, 1897- Serial No. 655,891. (No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM M. FARRAR, a citizen of the United States, residing at Hoboken, in the county of Hudson and State of New Jersey, have invented a certain new and useful Improvement in Car Propulsion, of which the following is a specification.

My invention relates to a new and useful improvement in car propulsion; and the object thereof is to provide a system for using compressed air and propelling street-cars and the like by a principle analogous to the trolley system for electricity. It may be also used for other purposes for which compressed air is now the motive power, as propelling trains, and pneumatic tubes for the transmission of small parcels, such as are being introduced in the post-office systems; but the apparatus here shown is especially designed for street-car service.

In order that those skilled in the art t which this invention appertains may understand how to make and use the same, the construction and operation will now be described in detail, referring to the accompanying drawings, forming a part of this specification, in which-e- Figure l-is a cross-section of a road-bed .and car embodying'my improvement; Fig.

2, a longitudinal section thereof; Fig. 3, an enlarged cross-section of the secondary main or supply-pipe and the traveling induction for receiving the compressed air from the main; Fig. 4:, a section of this main, taken at right angles to Fig. Sand showing the traveling induction mechanism in elevation, a portion of the latter being broken away at the lower end, so as to clearly illustrate the action of the valve-roll in its travel; and Fig. 5, a longitudinal section of one end of one of the sectional mains, showing the method of securing the valve-strip in place.

In the drawings, which show an apparatus adapted for use in connection with a doubletrack road, A represents the main conduit or supply-pipe, which is laid between the two tracks and supplies air underpressure to cars running upon both of said tracks, and its size and consequent construction is of course to be determined by the requirements of each case and depends upon the pressure carried, the number of cars, and the length of the line.

This air-main is connected at intervals of about six feet with the auxiliary mains B, laid in the center of each track, by means of the pipes 0. These auxiliary mains B are made of cast-iron and are rectangular boxes about six feet. in length,of the section shown in Figs. 1 and 3, being entirely closed, except for a slot 0 formed in the top, the entire length thereof, into which is fitted a strip of rubber D, the latter serving as a valve and having inserted therein stiffening-pieces E, of suitable material, such as iron, which render the valve rigid transversely, but preferably flexible longitudinally. The valve D is bent downward at its ends, as indicated at D, and held fast within this section of the main B by a dovetail slot D and it is also provided with a suitable number of springs F, which insure the return thereof to its seat after being opened in any part of its length, as will be hereinafter set forth.

The surface of the main B on each side of the valve-slot and the valve-seat are ground smooth, which maybe readily accomplished by means of a grinding-machine of emery or other abrasive material, as a perfectly plane surface is not required in either case.

Attached to the top of the main are curbs G, of rolled steel or other material, which form the sides of the slot at the surface of the street, and the main and rails forming the track are here shown as resting upon the metallic ties or foot-blocks'G embedded in the road-bed, as'is usually done in cable or underground-trolley construction; but while this construction is preferable it is not absolutely essential,- since in special cases a much cheaper arrangement'might be substituted therefor.

The trolley consists of a metal (preferably brass) box H, adapted to slide upon the upper surface of the main B and being provided with a soft-rubber packing H, as shown, where it comes in contact with the valve or sides of the slot. For lubricating the sliding metal surface of the trolley-box on the main B suitable grooves may be cut in the outer surface of the former, adapted to carry oil from a cup (here not shown)'carried on the trolley and leading to the sliding surface. The trolley-box H is provided with a small wheel or valve-roll I, so arranged that it v travels on the valve-strip and presses the same down immediately in contact therewith, as shown in Fig. 4, thus allowing the compressed air to pass into the box. To the top of the induction-box H is bolted a steel or other casting J, which is suitably ribbed and flanged and narrowed, so as to pass through the slot and yet have suiiicient strength to accomplish the purpose for which it is intended, and to further strengthen the same it is braced longitudinally by means of the tierods K, which are attached at their outer ends to the frame of the carin any suitable manner.

The upper end of the casting J has an extension J' formed therewith, which is threaded into the tube M, and resting upon the upper flange J of this casting is a spring N, which maybe adjusted by means of the screws J which bear against the cap-plate 0 and are threaded through the flange of the gland P. The object of this spring is to compensate for any irregularities in the track and at the same time to overcome the upper pressure transmitted to the lower end of the trolley by reason of its travel upon the valve strips and main. The gland P and stuflingbox Q, through which the tube M passes, are fastened to the frame of the car, and the stuffing-box fits against a washer-plate Q, which is placed into position after the checkvalve R and its seat-casing R, which also serves as a collar on the tube M, have been placed in position.

The air is led from the stuffing-box Q by means of the short pipes Q to the reservoirs S, and these will serve to equalize the pressure on the engines and also act as storage for a sufficient amount of compressed air to start the car if it should be stopped directly on the crossing or turnout, where the trolley would be momentarily disconnected from the supply-mains.

The engines in the car may be of any ordinary type and may be connected either directly or indirectly to the axles of the car; but as they form no part of my invention I do not deem it necessary to here illustrate the same. The general arrangement of a railway system embodying my improvement would be to have one or more power-houses located near but not necessarily contiguous to the line, but connected with the main A by an air-tight conduit. The power plant should consist of the proper boiler and air-compressing capacity. An air-reservoir would not be necessary, as the mains would serve that purpose and the air would be delivered from the compressor directly into said mains.

The present best-known system of propelling street-cars by compressed air is that in which air-tanks are carried under the car, filled with air of suflicient high pressure, (about two thousand pounds to the square inch,) and is adapted to run the car eight or ten miles before it becomes necessary to return to the power-house and have the reservoirs recharged; but obviously there are many serious disadvantages to the practical working of such a system,whereas the system here described is in every way analogous to the underground-trolley system, and the advantages over systems heretofore used are as follows:

First, cost of construction. The construction shown is the preferable one, although it might be modified so as to make it very much cheaper by omitting the cast-iron foot-piece or ties and substituting wooden cross-ties laid about two feet apart in a bed of loose broken stones. The track-mains B would rest directly on the cross-ties, and by using a wooden string-piece under the rails they might be brought up to the required level. The cost of the construction shown is, however, less than for a cable-road and compares favorably with an underground trolley. Of course the overhead trolley and the road-bed for the Hardie system are cheaper, but the former is not generally permitted in the heart of large cities. As regards the cost of cars, they would be cheaper under this system than any other except the cable-car. The power plants would also be much simpler and cheaper to construct. As compared with any trolley system we should require simply a directacting steam air-compressor against an engine, dynamo, and the various minor electrical devices for controlling the current. As compared with a cable plant, the latter requires large and powerful engines, costing comparatively a great deal of money and occupying a great deal of space. The Hardie system also re-' quires Very expensive machinery to compress the air to two thousand pounds per square inch and hold it in reserve for changing cars. The enormous loss due to heating the air in process of compression and the subsequent cooling,which it is almost impossible to avoid in dealing with such high pressure, must also be considered, as well as the additional ex pense of providing means for reheating the air on the car just prior to expansion, so as to prevent freezing in the exhaust-pipes, as it was found necessary to do in installing the Hardie system on the Manhattan elevated railway. These difficulties are easily obviated with moderate pressures and are items of economy in operation as well as in first cost. The system prepared requires the smallest amount of space for power-houses of any, and also the fact that it may be slightly removed from the line of the road gives it a decided advantage over the cable or I'Iardie system. These are important items of first cost in the heart of a great city where ground is valuable, especially on main thoroughfares.

Second, cost of operation. The practical efficiency of pneumatic transmission being about the same as that of electricity, and there being an extremely small loss of power on the pipe-line, it follows that the system proposed will compare favorably in cost of operation with the overhead trolley, while the difficulty of insulating the underground wire will render it more efficient than that system. The cable system entails an enor- 'mous loss of power due to the friction of the cable and its pulleys, bearings, &c., and this loss is a constant quantity, no matter how.

few cars are run, while in the case of the pneumatic trolley as soon as the consumption of air decreases on the line the flow decreases correspondingly in the mains, the pressurerises, and the automatic device on the compressor immediately checks the steam, so that the loss due to friction, &c., is exactly proportional to the power used. This item alone would mean the saving of many tons of coal per annum at any large plant. As compared with the Hardie system it is certainly much less expensive (per horsepower developed) to compress air to a pressure of one hundred and fifty to two hundred pounds per square inch than to two thousand pounds, and the loss due to leakage is of course tenfold greater in the latter case.

Third, safety tothe public. In the pneumatic-trolley system the car being driven by a traveling motor is entirely under the control of the motorman, rapid stopping being further facilitated by means of air-brakes. A car can be run at any speed desired on any part of the line, curves as well as tangents, and may be started from any point without the application of external force, and there is no possibility of a car being carried along against the will of the motorman, as is sometimes the case with cable-cars. It also has the advantage that no dangerous pressure or current is carried, as in the I-Iardie or trolley system. The pressure in any part of the car or line need not exceed from one hundred and fifty to two hundred pounds per square inch. There is with the Hardie system, in addition to the dangerous pressure carried and the terrible loss of life and the destruction of property which would follow the explosion of one of the air-reservoirs, which might be caused by a collision, or even without any external cause from some inherent defect in the reservoir itself, also the possibility of the air-supply giving out on the trip, leaving the car absolutely helpless and unable to return to its power-house. All this would be impossible with the pneumatic trolley system, and in addition crossings, turnouts, and curves of any radius which the car could turn in are entirely feasible.

Having thus fully described my invention, what I claim as new and useful is 1. The herein-described conduit consisting of oblong boxes placed end to end, each box being entirely closed except for a slot formed in the top thereof, a flexible strip closing said slot, said strip having its ends inserted in dovetail grooves in the box ends, substantially as described.

2. The herein-described conduit consisting of oblong boxes placed end to end, said boxes being entirely closed except for a slot formed in the top thereof, a flexible strip closing said slot, said strip having the ends thereof inserted in dovetail grooves in the ends of the box, and springs interposed between the bottom of the box and said strip, substantially as described.

3. The herein-described conduit consisting of oblong boxes placed end to end, each box being entirely closed except for a slot formed in the top thereof, a flexible strip closing said slot, said strip having its ends inserted in dovetail grooves in the ends of the box, strengthening ribs extending transversely across the strip, and springs interposed between the bottom of the box and the strip, as and for the purpose specified.

4. In combination with a main having a flexible strip arranged longitudinally therein acting as a valve, a box adapted to travel on the conduit, a roll journaled therein projecting below the end thereof to depress the valve, spring-pressed hollow connections between said box and the stuffing-box on the car, as and for the purpose described.

5. In combination with a main for supplying air to a traveling motor, flexible valve strips fitted to slots formed in said main, springs for holding said valve-strips normally closed, and strengthening-ribs for holding the valve strips rigid crosswise without interfering with their longitudinal flexibility, as specified.

6. A main for transmitting compressed air to a traveling motor, consisting of a series of,

sections closed except for a slot formed in each one thereof, a flexible valve-strip fitted to said slot so as to normally prevent the outflow of the air, strengthening-ribs carried by said strip, springs for normally holding said strip closed, and a suitable traveling induction device adapted to work in conjunction with said sections, and valve-strips for permitting the upfiow of the compressed air from the main to the motor, as specified.

7. In combination with a main of the character described, an induction device consistin g of a box adapted to travel upon said main, a roll journaled within said box for opening the valves beneath the box, a suitable casting connected with the box adapted to project through a curbing-slot, a tube to which the casting is secured, a stuffing-box through which said tube passes, a spring for normally forcing the device downward, a check-valve for preventing the retrograde flow of the air, and reservoir-tanks to which the stuffing-box is connected by pipes, substantially as and for the purpose set forth.

In testimony whereof I have hereunto affixed my signature in the presence of two subscribing witnesses.

WILLIAM M. FARRAR. 

